Starting apparatus for internal combustion engines



A; WEISS March 21, 1939.

STARTING APPARATUS FOR INTERNAL COMBUSTION ENGINES Filed June 9, 1957 4 Sheets-Sheet l LN OJ M f j Q 2 0 i: a 2 2 m i A w b w o 4/ \l. E m5 ,1, w w f HM 1 8 I1 5 2 ww M w J n M a Q Q A. WEISS March 21, 1939.

STARTING APPARATUS FOR INTERNAL COMBUSTION ENGINES Fil ed June 9, 1937 4 Sheets-Sheet 2 A. WEISS March 21, 1939;

STARTING APPARATUS FOR INTERNAL COMBUSTION ENGINES Filed June 9; 1937 4 Sheets-Sheet .3

March 21, 1939.

4 Sheets-Sheet 4 Filed June 9, 1937 Patented Mar. 21, 1939 UNITED STATES STARTING APPARATUS FOR. INTERNAL CODIBUSTION ENGINES Adolf Weiss, Marbach, Germany, assignor to Robert Bosch Gesellschaft mit beschrankter Haitang Application June 9, 1937, Serial No. 147,338 In Germany June 11, 1938 19 Claims. (01. 290-38) The invention relates to a startingapparatus for internal combustion engines of the type wherein the pinion is secured against premature disengagement by a holding member, and can be released at will by the driver. The object of the present invention is to improve starting apparatus of this type, and thereby to still further simplify and cheapen it. In the starting apparatus of the patent application Serial No. 131472, of Albert Callsen and Adolf Weiss, filed March 17, .1937, the pinion engages from the position of rest outwardly by rotation. This kind of engagement presupposes at least in heavy starters, that the pinion engages only with the engine flywheel at a small rotation speed and with small inertia. For this kind of engagement, a two stage switch is necessary which in the first switching stage switches in a resistance before the starter which is then short circuited in the second switching stage.

According to the present invention, the two stage switch'and the switched in'resistance are avoided in such a manner that through a control member which serves to secure the pinion in engagement with the flywheel in the engaging position, the pinion is also displaced longitudinally till it has at least partly come into engagement with the flywheel of the engine.

In the accompanying drawings are illustrated two forms of construction of the present invention.

In the drawings:

Figure 1 is a longitudinal sectional view of one form of electric starter with the parts in their inoperative position. I

Figure 2 is a similar view but with the parts in an intermediate position taken up during the starting operation. Figure 3 is a similar view but with the parts in that position in which the starter is fully operative.

Figure 4 is a longitudinal sectional view of a modified form of starter.

Figure 5 is a similar view but with the starter on the thread II the nut I! of a disc coupling 2| is in screw threaded engagement. The nut is forms the driven part of the coupling, whilst the driving part is formed by a drum 2i keyed on to the armature shaft ll. Between the drum- 2| 5 and the nut l9 are arranged a number of friction discs 22 which, during the drive of the starter,- are pressed between the nut and an abutment consisting of spring discs 23.

Collars 24, 25 are fitted on the hollow shaft i4 near the ends thereof. The collar 24 serves to limit the motion of the pinion l8, and the collar 25 forms an abutment for the spring discs 23. The collar 25 in the position of rest of the starter, is distant about 5 or 6 mm. from the spring discs 23, whilst the pinion IS in its position of rest is distant about 3 or 4 mm. from the geared flywheel 26 of the engine to be started. The reason for these distances will become clear in the later description of the method of operation.

In the hollow shaft l4 lies a control rod 21. which passes wholly through the armature of the starting motor. On that side of the starting motor remote from the pinion Hi. there is provided an electromagnet with a core II which is adapted to actuate a lever 28 and a switch with switch contacts 29 and a switch bridge 30 by which the starting motor may be connected to a battery.

One end of the lever acts upon a cap SI and a 30 spring 32, on the control rod 21, which at that end adjacent thepinion I8 is provided with a head 33 which has a peripheral groove 42, the side walls of which are conical as shown at 34. Adjacent this groove the hollow shaft is radially 35 bored at 35, in which bore a ball 36 is housed, the periphery of which extends into the groove of the control rod. The hole 35 is so positioned that the base of the.internally threaded part of the pinion lies beyond it when the pinion beam 40 against the collar 24, i. e. in that position of the pinion the hole lies opposite a part of the pinion of enlarged bore. A return spring I4 is disposed between the armature shaft II and a collar 43 of the control rod 21. 45

The starting apparatus works as follows:

In order to operate the starting apparatus when the parts are in the position shown in Figure 1, the driver actuates an electric switch 45 for an electromagnet 40 whereby the latter is so excited and the core 4| displaced to rock the lever 28, and which, in turn, moves the control 21 through the medium of the collar 3| and the spring 32. v

The control rod on its periphery presses on the sphere 38, which in this position of the starter cannot move radially outwards, and thus displaces the hollow shaft I4 with the pinion la, the displacement being such that the pinion IS ongages with the geared flywheel 25. Simultaneously therewith the collar 25 reaches that position in which it abuts against the spring discs 25. Since the collar 25 in order to reach the spring discs must travel further than the distance between the pinion and the flywheel 26 a secure engagement of the pinion is eflZected since in all cases the coupling can only become effective if the pinion is already in engagement. On displacement of the core 4! the contact bridge 30 of the electromagnet is also displaced to touch the contact strips 29 whereby the starting motor is connected to its source of electrical supply such as a battery. This position of the starter is shown in Figure 2.

on closing of the contact the armature on the shaft ll begins to rotate, and thus rotation is transmitted to the externally threaded shaft l4 by the friction disc coupling 20. The pinion l8 being held from rotation by the flywheel gear 26 is screwed forward along the shaft I4 until it abuts against the collar 24 on the shaft and the position shown in Fig. 3 is reached. In this position the ball 35 can now move radially outwards in the hole 35, and is assisted in this by the sloping surface 34 of the peripheral groove in the control rod. The control rod also completes its forward movement under the action of the spring 32 which is compressed by the lever 28 under the control of the electromagnet.

It will be appreciated that in this position the disengagement of the pinion from the flywheel is prevented by the ball until the driver switches off the electromagnet.

Should the driver, after the running of the motor, first open the switch, the starter can not become injured, because the friction disc clutch immediately responds, and thus the rotation of the pinion is not transmitted to the armature of the starting motor. After the opening of the switch 45 the spring 44 pushes back the control rod 21, whereby the groove 42 of the control rod reaches a position radially of the ball so that this can move radially inwards, and permits the pinion to screw back on the shaft l4. Moreover the lever 28 with the core 4| is again brought back to the original position by the control rod.

The modified form of construction according to Figs. 4 and 5 shows the application of the inventiomto a starter with a longitudinal displaceable armature. In this construction the starter has a hollow armature shaft 50, which is mounted for longitudinal displacement in spaced bearings 5|, 52. The shaft projects through the bearing 52 and is provided on the projecting part with a thread 53 on which a pinion 54 can screw itself forwards. On the end of the hollow shaft is arranged a collar 55 whilst between the collar and the pinion is provided a buffer spring 56 against one end of which the pinion can abut after engagement with the flywheel 6|.

As in the first example the shaft 50 has a hole 51 in which is seated a ball 58 whilst internally of the hollow shaft lies a control rod 59 which passes wholly through the starter and is fastened at one end to the bearing 5|. At the part of the hollow shaft which projects beyond the bearing 52, the bore in the hollow shaft ll widened and correspondingly the rod 59 is also of greater diameter at this end. The change from the wider to narrower part is formed by a conical surface 50 which in the position of rest of the starter lies approximately 6 mm. away from the ball while the geared flywheel Si is only distant from the pinion by approximately 3 mm. so that in all cases the pinion comes into engagement with the geared flywheel before the sphere is moved outwards by the conical face 60. A tension spring 62 is arranged between the collar 63 on the hollow shaft and the bearing 52.

On operating this modified form of starting apparatus the armature with the hollow shaft is displaced on being energised so that the pinion 54 provided on the shaft 50 is also displaced until it engages for a little way in the geared flywheel 6|. The remainder of the engagement path of displacement of the pinion is effected by the pinion screwing forwards on the hollow axle. In the end position the hollow shaft is so far pushed forward, that the ball is pressed radially outwards by the conical surface and the screwing back of the gear wheel is prevented (see Fig. 5). In this example, the hollow displaceable shaft acts as the control member which pushes the ball against the conical face.

I declare that what I claim is:

1. An internal combustion engine starter comprising an electric motor, an element driven by said motor, means both for displacing said element to a position where it is coupled to the engine automatically upon closure of the circuit of said electromotor and also for locking said coupling in its fully engaged position during the total time of closure of said electric motor circult. and electromagnetic means for controlling the operation of said means.

2. An internal combustion engine starter comprising an electric motor, a coupling element between said electric motor and the engine which element is displaced automatically into its engagement position on the closing of the circuit of said electric motor, a slipping clutch between said electric motor and the element driven thereby, means to engage said clutch fully to transmit total torque of said motor only when the coupling is fully engaged, control means both to displace said coupling element on closing of said motor circuit and to lock said coupling when fully engaged, and means to disconnect said look only on breaking of said electric motor circuit.

3. An internal combustion engine starter comprising an electric motor, a driving element driven thereby, means both for automatically clutching said driving element to said engine on the closing of said motor circuit and for locking said clutch in its engaged position, an electromagnetic control means for said clutching and looking means and means to release said lock on the breaking of the motor circuit.

4. An internal combustion engine starter as claimed in claim 2 in which the coupling element is in the form of a pinion adapted for engagement with the flywheel of the engine to be started, and the control means include an externally threaded shaft carrying said pinion and means to displace said shaft longitudinally to bring said pinion into engagement with said flywheel.

5. An internal combustion engine starter as claimed in claim 2 in which the coupling element is in the form of a pinion, and the control means include a threaded shaft on which said pinion is longitudinally displaceable and a control member axially displaceable internally of said shaft for ing member with a part of the engine to be longitudinally displacing said pinion and said shaft in unison.

6. An internal combustion engine starter as claimed in claim 2 in which the coupling element is in the form of a pinion, and the control means include a threaded shaft on which said pinion is longitudinally displaceable, a control member axially displaceable internally of said shaft for longitudinally displacing said pinion and said shaft in unison and electromagnetically operated means for longitudinally displacing said control member.

7. An internal combustion engine starter as claimed in claim 2 in which the coupling element is in the form of a pinion, and the control means include a threaded shaft on which the pinion is mounted, means for moving said haft and said pinion in unison and means for moving said pinion by a further amount independently of said shaft to cause complete engagement of said pinion with said engine to be started.

8. An internal combustion engine starter as claimed in claim 2 in which the control means for the coupling element includes a two-armed lever and an electromagnet housed adjacent the periphery of the starter for actuating said lever.

9. An internal combustion engine starter as claimed in claim 2 in which the control means includes a radially-bored shaft and a control member in the form of a rod passing through said shaft and having a conical face adjacent said bore in said shaft, and a ball housed in said radial bore for displacement in a direction radially outwardly thereof on engagement of the ball by the conical face of said control rod to permit independent displacement of said control rod with respect to said shaft.

10. An internal combustion engine starter comprising an electric motor, a driving element driven thereby, means for automatically coupling said driving element to said engine upon the closing of the circuit of said electric motor and for locking said driving element in its engaged position, control means for said coupling and locking means, and means to release said locking means on the? breaking of the motor circuit.

iii)

11. An internal combustion engine starter as claimed in claim 11 wherein the armature of the electric motor is axially displaceable and wherein the driving element is in the form of a pinion which is moved into engagement with the flywheel of the engine to be started by the axial dis- .placement of said armature and is held in its engaged position thereby.

12. An internal combustion engine starter as set out in claim 11in which the driving element is in the form of a pinion and the means for automatically coupling said pinion to said engine include an externally threaded axially displaceable shaft driven by said motor and on which said pinion is mounted for movement with said shaft and also for movement relative thereto, said pinion being initially coupled to said engine by movement of said pinion with said shaft and fully coupled by subsequent movement of said pinion relative to said shaft.

13. An internal combustion engine starter vcomprising an electricmotor, a threaded shaft started upon closure of the circuit of said electric motor, said driving member screwing along said threaded shaft after initial engagement to complete full engagement of said driving mem her with said engine, means for locking said driving member in its engaged position, and means for releasing said locking means upon breaking of the circuit of said motor.

14. An internal combustion engine starter comprising an electric motor, a threaded shaft driven by said motor, a driving member in threaded engagement with said shaft for axial displacement thereon to engage and disengage said engine, a stop member for holding said driving member inengaged position after engagement with said engine, and control means for displacing said shaft and driving member to engage said driving member with said engine and for controlling the operation of said stop member.

15. An internal combustion engine starter comprising an electric motor, an axially displaceable threaded shaft driven by said motor, a driving member in threaded engagement with said shaft for axial displacement thereon and therewith to engage and disengage said engine, a stop member for holding said driving member in engaged position after engagement thereof with said engine, and control means for displacing said shaft and driving member to cause said driving member to engage said engine and for controlling said stop member.

16. An internal combustion engine starter comprising an electric motor, a threaded shaft, a

friction clutch between said shaft and motor, a coupling member in threaded engagement with said shaft for axial displacement thereon to engage and disengage said engine, means to engage said clutch fully to transmit the full torque of said motor only when the coupling member is fully engaged, a stop member for holding said coupling member in engaged position after en gagement with said engine, and control means for displacing said shaft and coupling member to engage said coupling member with said engine and for controlling the operation of said stop member.

1'7. An internal combustion engine starter comprising an electric motor, a threaded shaft, a

' friction clutch between said shaft and motor, a

tric motor, said coupling member screwing along said threaded shaft after initial engagement to complete full engagement of said coupling member with said engine, means to engage said clutch fully to transmit full torque of said motor only when the coupling member is fully engaged, means for locking said coupling member in its engaged position, and means for releasing said locking means upon breaking of the circuit of said motor. I

18. An internal combustion engine starter as set out in claim 17 in which the means to engage said clutch includes a pressure member in threaded engagement with said threaded shaft, said pressure member screwing along said threaded shaft after initial engagement of said coupling member with said engine to fully engage said clutch to transmit full torque of said motor after said coupling member is fully engaged.

fully engaged, a stop member for holding said coupling member in engaged position after engagement with said engine, and control means for displacing said shaft and coupling member to engage said coupling member with said engine and for controlling the operation of said stop member and said clutch.

ADOLF WEISS.

CERTIFICATE OF CORRECTION Patent No 2,151,) 92.

March 21, 1959.

ADOLF WEISS It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, 1ines'l. .9 and 57, claims 11 and 12 respectively, for the claim reference numeral "11'' read 10; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of June, A. D. 1959.

(Seal) Henry Van Arsdele acting Commissioner of Patents. 

